A strap fixed before anyone sees it is just a strap. Hair brushed back before the conversation starts barely registers.
The version he remembers happens after his eyes mess up. She catches the glance. Waits. Then a thumb slips under the necklace chain, or she pulls the sleeve back into place, or smooths the skirt with one hand before looking up again.
Nothing big enough to accuse her of. That is the problem. The order is already stuck in his head: look, pause, adjustment, that almost-smile he will swear was there even if it was not.